diff --git a/.flowconfig b/.flowconfig
index 43933cd5d5e..c857eaa1da0 100644
--- a/.flowconfig
+++ b/.flowconfig
@@ -51,6 +51,8 @@ suppress_type=$FlowFixMeProps
 suppress_type=$FlowFixMeState
 suppress_type=$FlowFixMeEmpty
 
+experimental.env_mode=constrain_writes
+
 [lints]
 sketchy-null-number=warn
 sketchy-null-mixed=warn
diff --git a/.flowconfig.android b/.flowconfig.android
index 2aacfc7c2e8..c67ab5fb840 100644
--- a/.flowconfig.android
+++ b/.flowconfig.android
@@ -51,6 +51,8 @@ suppress_type=$FlowFixMeProps
 suppress_type=$FlowFixMeState
 suppress_type=$FlowFixMeEmpty
 
+experimental.env_mode=constrain_writes
+
 [lints]
 sketchy-null-number=warn
 sketchy-null-mixed=warn